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State and trends


the landmark collaborative 2005 Millennium Ecosystem Assessment: marine, coastal, inland water, forest, dryland, island, mountain, polar, cultivated (including agricultural) and – often overlooked but increasingly important – urban ecosystems (MA 2005). North America is perhaps unique in its diversity of ecosystems, and Canadian and American citizens have benefitted enormously from this diversity because of the range of ecosystem services they provide.


2.3.2 Species: a broad overview


Although successful recovery programmes have been established for many species, North American biodiversity is on the decline. In Canada, for example, mainly because of habitat degradation and loss, 20 per cent of native amphibians – frogs, toads and salamanders – are considered at risk of extinction. Declines in several


amphibian


populations since the mid-1990s have been documented in the Great Lakes Basin and the St. Lawrence River corridor; trends for western Canada are not as well documented (Federal, Provincial, Territorial Governments of Canada 2010). A study by the US Geological Survey (USGS) released in 2013 indicated that amphibian populations are declining at “precipitous rates… from the swamps in Louisiana and Florida to the high mountains of the Sierra and Rockies” (Adams et al. 2013). Similar concerns have been raised about pollinators threatened by habitat loss and fragmentation, pathogens, and the improper use of pesticides, in line with global trends (FWS 2015; Archer et al. 2014; Godfray et al. 2014; Vanbergen 2014; Potts et al. 2010). Pollinator decline has implications far beyond species loss, since pollinators play a key role in many managed and natural ecosystems.


Some recently noted extinctions are in fact less


contemporary. In mid-July 2015 the US Fish and Wildlife Service recommended the delisting of the eastern cougar (Puma concolor couguar) from the endangered species list, in effect declaring it extinct. The eastern cougar subspecies was listed as endangered in 1973. Accounts suggest, however, that most eastern cougars disappeared in the 1800s as European immigrants killed cougars in efforts to protect themselves and their livestock, forests were converted


to agricultural use, and white-tailed deer (Odocoileus virginianus), the cougar’s primary prey, nearly went extinct in eastern North America. The last records of sighted eastern cougars are believed to be in Maine (1938) and New Brunswick (1932). The delisting is a reminder of the very real consequences of both overhunting and habitat destruction; and the endangered Florida panther may not be far behind, despite successful genetic restoration efforts (Johnson et al. 2010).


However, there is also a myriad of successful recoveries that are worth emphasizing. The most heralded case may be the American bald eagle (Haliaeetus leucocephalus), once considered on the brink of extinction, mainly because


of persistent organic pollutants such as dichlorodiphenyltrichloroethane (DDT).


Although there


are many other causes predating the introduction of DDT, including the removal of important winter foods and habitat change, it is unlikely that this iconic species would still exist today had it not been for continent-wide bans on the use of DDT to control marshland mosquitoes (Gerrard and Bortolotti 2014) and other insects. The recoveries of the grey whale (Eschrichtius robustus) from commercial whaling, and of several subspecies of seal, are other examples of the effectiveness of hunting restrictions. Figure 2.3.1 provides more on other species that have made noticeable recoveries in the Canadian context.


2.3.3 International agreements


The CBD provides an overall framework for addressing biodiversity issues, including species loss, at the international level. All UN member states except the US are Parties to the CBD. Its Strategic Plan 2011–2020 and the associated Aichi Biodiversity Targets provide some very clear targets for reversing losses to species, ecosystems and genetic resources.


Other agreements address specific species or specific threats. For example, there has been some debate on the status of the polar bear (Ursus maritimus) in different Arctic countries, including the US and Canada. While the polar bear


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